Many food products, before they can be packaged or consumed, must be subjected to a variety of heat treating processes. The product may need to be blanched, cooled, or cooked, or may require multiple heat treatments. Large quantities of product may be treated in a rotating drum with an internal auger for advancement of the product through a heated or cooled water bath. The efficiency of the process, as well as the time which is consumed in properly heating or cooling the product, depends on the heat transfer rate between the treated product and the surrounding liquid. An increased rate of heat transfer means a decreased retention time of the product required within the treatment apparatus, and hence allows a greater throughput for a given size machine.
It has been found that agitation of food product with a significant thickness, such as animal organs, or pouches of liquid or semi-liquid product, results in improved heat transfer. As disclosed in my prior U.S. Pat. No. 4,875,344 for a CHILLER, axially extending baffles peripherally mounted to the rotating auger flights of a cylinder are effective in imparting some agitation to a conveyed food product. My prior patent also discloses improved agitation achieved by air manifolds positioned within the cooler tank which discharge air into the cooling liquid to assist in manipulating and agitating the treated food product. Air-assisted agitation within a cooler is effective, but requires the provision of a source of compressed air with the attendant cost.
What is needed is a rotating cylinder cooler which promotes improved heat transfer from treated products in a more cost-effective manner.